This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Development of isoform selective NOS inhibitors continues to be the central focus of this proposal. Based on structural information gathered during the two previous proposal periods, a new generation of nNOS selective inhibitors were designed de novo (ref. 1). The new compounds were screened through in vitro inhibitory assays. Those shown to have good potency and selectivity were then used for structural studies. The best inhibitors were also found to protect against cerebral palsy induced by brain hypoxia in pre-clinical animal tests (ref.2). The enzyme-inhibitor complex structures are critical for further modification and improvement of new inhibitors. Therefore, we would like to extend the proposal for another two years.